Television receivers capable of displaying desired characters such as teletext on a picture displayed on a cathode-ray tube (CRT) in a superimposed fashion are commercially available on the market. In that case, known television receivers are adapted to add a character display signal generated by a character generating circuit or the like to a video signal immediately before a CRT.
On one hand, a television receiver having a CRT of a wide aspect ratio of 16:9 is now commercially available on the market. FIG. 1 of the accompanying drawings shows an example of such television receiver having a CRT of a wide aspect ratio.
If such television receiver displays a video signal formed with an aspect ratio of 4:3 by using the whole of a display screen, the video signal is inevitably enlarged in the horizontal direction and displayed. Accordingly, when a character display signal with a similar aspect ratio of 4:3 is displayed, characters to be displayed are enlarged in the horizontal direction.
On the other hand, a display apparatus in which a display screen is divided into multiple display screens such as two display screens and video signals thereof are compressed in the horizontal direction to thereby display substantially normal pictures are also commercially available on the market. However, a technique for compressing a character display signal has not yet been proposed so far. Accordingly, according to the above-mentioned method for adding the character display signal to the video signal immediately before the CRT, pictures cannot be displayed on the multiple display screens such as two display screens.
In television receivers capable of double-speed scanning in which a video signal is scanned by double scanning lines in order to prevent a flicker from being produced on a picture, when a video signal is processed in a double-scanning fashion, horizontal deflection is carried out at a speed twice the normal speed so that characters to be displayed are enlarged twice in the horizontal direction.
When characters, etc., are displayed by the television receiver in which a video signal is processed in a multiple-screen display fashion so that a picture is displayed on two display screens or the like and in a double-speed scanning fashion, character display signals of RGB three primary colors signal are temporarily converted in to video signals such as Y/U/V. The thus converted video signals are processed in a multiple-screen display fashion and in a double-speed scanning fashion together with other video signals, thereby pictures being displayed on two display screens or the like in a multiple-screen display fashion.
However, when such processing is carried out, a frequency band used in such processing is limited. As a consequence, a frequency band of a character display signal such as a small character having a high frequency component is limited so that it becomes impossible to display such a small character.